Which amp? Alpine MRP-F550, PG xenon 100.4, kicker Kicker ZX650.4

Guys,

Which amp?

I originally bought the xenon 100.4 to power my mb quart pce 216 and infinity ref, but vendor sent me a used amp whick they claimed to be new. Anyways I got my money back and now I am rethinking the amp again.

Right now, I am using PG Octane R5.04. Looking to replace it. Which amps would u recommend?